Hermione returned her Time Turner at the end of her third year, no longer wanting to do her extra classes she was using the Turner for that year. In their fifth year, Harry, Ron, Hermione, Ginny, Neville and Luna smashed the entire Ministry stock of Time Turners while fighting and running through various rooms in the Ministry of Magic.

While this is true, it's also ******* retarded. You'd think that other people would still have some, and it's not like anyone used them to prevent murder before they broke them all. Time travel just should have been left out of that book

It's also a matter that Time Turners don't actually change the past, they only make the inevitable happen...it's weird...like the whole thing with Harry going back in time to do the Patronus, he didn't know it was himself until the moment he did it, but it happened before he used the time turner, so you don't actually change the past, you just make the past happen.

Time Travel was described as a very touchy subject, which is why Hermione was restricted to only using it for her multiple classes. Dumbledore was only able to figure out a way to utilize it to save two lives within the immediate events what was going on. The ministry restricts the use of Time Turners, so they're seldom used by anyone. It took McGonagall a buttload of work to convince the Ministry to allow Hermione to use one. It was by circumstance that Harry and Hermione were capable of rescuing Sirius and Buckbeak.